Belt sanding machine

ABSTRACT

THE IDLER DRUM OF A BELT SANDING MACHINE IS SUPPORTED CANTILEVER STYLE FROM AN UPRIGHT WALL OF THE MACHINE FRAME AT A LOCATION A DISTANCE ABOVE A POWER DRIVEN CONTACT DRUM, BOTH FOR VERTICAL MOTION RELATIVE TO THE CONTACT DRUM AND FOR TILTING MOTION ABOUT A HORIZONTAL AXIS DISPOSED CLOSE TO SAID WALL. THE BED ALONG WHICH ARTICLES TO BE SANDED ARE ADVANCED UNDER THE CONTACT DRUM, IS MOUNTED ON A SLIDE UNIT WHICH IS CONSTRAINED TO VERTICAL ADJUSTING MOTION ALONG RAILS PROVIDED BY THE OPPOSITE SIDE EDGES OF THE UPRIGHT FRAME WALL. A PLAIN ENDLESS CONVEYOR BELT ON THE BED CAN BE REPLACED BY AN ABRASIVE BELT OF THE SAME TYPE AND SIZE PROVIDED FOR THE CONTACT AND IDLER DRUMS.

Sept. 28, 1971 R Q FMR, JRI ETAL 3,608,245

y BELT SANDING MACHINE Filed sept. 4. 1969 4 sheets-sheet 1 Q "uw um 8077 76 f. 838/ Sept. 28, 1971 R, G, FMR, Jpg,1 ETAL 3,608,245

BELT SAND-ING MACHINE @ned sept. 4. 1969 4 Sheets-sheet 2 Sept. 28, 1971R, G, FMR, 1R1 ETAL 3,608,245

BELT SANDING MACHINE Filed Sept. 4. 1969 4 Sheets-Sheet 5 Sept., 28,1971 R, G, FMR, JR ETAL 3,608,245

BELT SANDING MACHINE Filed Sept. 4. 1969 4 Sheets-Sheet 4.

United Stes Patent 3,608,245 BELT SANDING MACHINE Raymond G. Fair, Jr.,and Cecil D. Brotherton, Minneapolis, Minn., assignors to TimesaversSanders, Inc., Minneapolis, Minn.

Filed Sept. 4, 1969, Ser. No. 855,196 Int. Cl. B24b 21/18, 21/04 U.S.Cl. 51--135 3 Claims ABSTRACT F THE DISCLOSURE The idler drum of a beltsanding machine is supported cantilever style from an upright Wall ofthe machine frame at a location a distance above a power driven contactdrum, both for vertical motion relative to the contact drum and fortilting motion about a horizontal axis disposed close to said wall. Thebed along which articles to be sanded are advanced under the contactdrum, is mounted on a slide unit which is constrained to verticaladjusting motion along7 rails provided by the opposite side edges of theupright frame wall. A plain endless conveyor belt on the bed can bereplaced by an abrasive belt of the same type and size provided for thecontact and idler drums.

This invention relates to belt sanding machines of the type having anendless abrasive belt trained over contact and idler drums which areconstrained to rotate on parallel axes with the driving drum spaced adistance below the idler drum but above the top stretch of an endlessconveyor belt that travels over a horizontal work supporting bed.Articles to be sanded are placed upon the conveyor and advanced therebythrough a sanding zone under the contact drum.

One of the objects of the invention is to provide a belt sanding machineof the character described with simplified and inexpensive adjustingmechanism that enables the idler drum to be readily moved bodily for theachievement of the proper tension on the abrasive belt trainedthereover, and to also enable the idler drum to be tilted lengthwise asneeded to keep the endless abrasive belt running true on the drums.

Another object of the invention resides in the provision of simplifiedstructure that can be readily fabricated at low cost from ordinary barstock, by which the Work supporting bed can be mounted on an uprightwall of the machine frame in an exceptionally stable fashion and foraccurate adjustment toward and from the contact drum over which theabrasive belt is trained.

Still another object of the invention resides in the provision of a beltsanding machine of the character described with a work conveyor beltthat can be removed and replaced by an endless abrasive belt of the samesize and type provided for the driving and idler drums.

With these observations and objects in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawings. This disclosure is intendedmerely to exemplify the invention. The invention is not limited to theparticular structure disclosed, and changes can be made therein whichlie within the scope of the appended claims without departing from theinvention.

The drawings illustrate one complete example of the physical embodimentof the invention constructed according to the best mode so far devisedfor the practical application of the principles thereof, and in which:

3,608,245 Patented Sept. 28, 1971 FIG. l is a perspective view of a beltsanding machine of this invention;

FIG. 2 is a front elevational view of the machine, at an enlarged scale;

FIG. 3 is an elevation of the machine, viewing the same from itsdelivery side;

FIG. 4 is a fragmentary perspective view of the idler drum adjustingmechanism; and

FIG. 5 is a fragmentary perspective view illustrating the slide unitwhich carries the conveyor bed for Vertical adjustment on the machineframe.

Referring now to the accompanying drawings, the numeral 10 generallydesignates the frame of a belt sanding machine of this invention. Theframe shown comprises a horizontal base plate 11, and a ilat plate-likesupporting wall 12 secured to the base and rising vertically therefrom.

Castings having burrs that can be removed by sanding, or other articlesto be sanded, are conducted through a sanding zone generally designated13, by means of a feed conveyor 14 comprising an endless belt having ahorizontal top stretch 15 extending lengthwise across the front face ofthe wall 12, and upon which the articles are placed.

As will be described later, the upright supporting wall 12 of themachine frame is provided with a slide structure 16 to mount theconveyor thereon for up and down adjusting'motion along the front faceof said wall.

Articles to be sanded are loaded onto the right hand end of theconveyor, as viewed in FIG. 2, and as they travel through the sandingzone 13, they are engaged with and acted upon by an endless abrasivebelt 17 as it passes around the underside 0f a power driven contact drum18. The drum 18 is spaced above the upper stretch 15 of the conveyorbelt14, and it extends forwardly thereacross from the wall 12. It rotates ona horizontal axis parallel to but spaced a distance below that of anidler drum 19 over which the upper portion of the abrasive belt istrained. The idler and contact drums are both carried by the uprightwall 12 of the frame, and they cooperate to constrain the oppositestretches of the abrasive belt 17 to substantially vertical travel.

The endless feed conveyor belt is trained over spaced apart driving anddriven rolls 20 and 21, respectively, which are constrained to rotate onaxes lying in a common horizontal plane and parallel to the axes of thecontact and idler drums 18 and 19. The rolls 20 and 21 have an axiallength substantially equal to that of the contact and idler drums, andthe conveyor belt 14 also has a width substantially equal to that of theendless abrasive belt 17. As `will be discussed again hereinafter, it isa feature of this invention that an abrasive belt such as a replacementfor the belt 17 can be used interchangeably with the conveyor belt 14.

The belt conveyor 14 comprises part of a Work supporting bed, generallydesignated 22, of inverted channel shape providing a flat back or web 23and opposite front and rear side flanges 24 and 25, respectively,depending from the web and substantially parallel to the front face ofthe upright wall 12 of the frame.. The bed flanges are spaced apart adistance slightly greater than the axial dimension of the rolls 20 and21. The driven roll 21 is freely rotatably mounted on a spindle 26 whichextends axially between portions of the channel flanges that extendbeyond the web of the channel at the feed end of the conveyor. flattenedends on the spindle 26 are slidably received in horizontal slots 27 inthe flange extensions that allow the spindle and the driven roll thereonto be moved bodily toward and from the sanding zone, for belt tighteningpurposes, and also to enable removal and replacement of the conveyorbelt. Adjusting screws 28 threaded through the opposite ends of thespindle and bearing against the bottoms of the slots 27 provide for suchadjustment ofthe driven roll.

The drive roll is fixed to the output shaft 29 of a speed reduction unit30, which output shaft has its forward end rotatably journalled in anextension of the forward channel flange 24 at the delivery end of theconveyor.

As will now be described, the speed reducing unit is xed to the sameslide unit 16 to which the work supporting bed is secured. Hence, thespeed reducer can be considered a part of the supporting bed assembly.

The slide unit 16 is of exceptionally simple construction in that it canbe fabricated entirely from bar stock. However, it requires the upright|wall 12 of the frame to have straight and parallel opposite side edgeportions of uniform thickness, and each to define a rail 32. The slideunit comprises a channel shaped guide 33 slidingly embracing each railand constrained thereby to vertical motion relative to the frame. -Eachchannel shaped guide 33 has opposite front and rear anges 34 and 35,respectively, which slidingly engage over the rails and which areprovided by a pair of elongated tlat bars. Each guide also has anelongated web 36 in lengthwise juxtaposition to the adjacent edge of thewall 12, and which web is confined as a spacer bar between the flangebars, being secured thereto by bolts 37.

The rear flange of the work supporting bed 22 bears flatwise against thefront anges 34 of both guide channels, and it is secured to the lowerportions of the latter by screws 38 which are threaded into tapped holesin the guide flanges 34. Such securement of the supporting bed to theguide channels serves to hold their lower portions opposite one anotherand at the proper spacing for free sliding motion along the oppositeside edges of the frame wall 12.

The guide channels are also joined together at their rear, by a crossbar 40 of angle shaped cross section. The upright leg 41 of the crossbar 40 extends horizontally between upper portions of the rear flanges35, to which it is atwise secured by the upper ones of the bolts 37which fasten the slide bars 34, 35 and 36 together. The horizontalflange 43 of the cross bar extends rearwardly from the slide unit 16 andhas a nut 44 secured to its top, for the reception of a verticallydisposed adjusting screw 45. Rotation is imparted to the screw 45 in onedirection or the other by a hand lever 46 which has a ratchet connection47 with the screw. The ratchet mechanism, which is located at the innerend of the hand lever 46, is supported on a ledge 48 secured to the backof the supporting wall 12 above the angle bar 40. The ledge has a holetherein sized to loosely receive the adjusting screw.

From the description thus far, it will be apparent that the slide unit16 and the feed conveyor thereon will be bodily lifted up or lowered asdesired, merely by rotation of the adjusting screw 45 in the properdirection. This, of course, enables the throat under the contact drum,at the sanding zone, to be set to a dimension having the properrelationship to the thickness of the article to be sanded.

The speed reducer 30 is shown in solid lines in`FIG.2 but only in brokenlines in FIG. 3. It is fastened to a mounting plate 49 which in turn issecured by screws 50 to the bars 34 and 35 of the slide unit at thedelivery side of the machine. These. screws are threaded into tappedholes in the outer edges of said bars. Consequently, the speed reduceris adjusted up and down in unison with the feed conveyor.

The input shaft of the speed reducer is provided with a V pulley 52 andit is driven from an electric motor 54 4 through a V belt 55. The motorS4 is secured to an upright gusset plate 56 which in turn, is xed to thebase plate 11 and to the back of the supporting wall 12 to reinforce thesame. The V belt 55 is also trained over a belt tightener pulley 58which functions to maintain good tension on the belt 55 despite the moreor less limited range of up and down movement allowed the speed reducerand the feed conveyor in unison with one another. While the motor shaftis connected with the drive roll 20 of the feed conveyor through a speedreducing unit, it is directly drivingly connected with the contact drumthrough a coaxial coupling 59.

The Contact drum 18 is rotatably carried by a bracket 60 which has a atmounting flange 61 secured to the supporting wall 12 by bolts 62 whichatwise clamp the flange against the front face of the wall. The endportion of the contact drum which is coupled to the motor shaft issupported by a bearing carried by the bracket flange 61. The front endof the contact drum is rotatably carried by an outboard bearing 63secured to the forward end of a hanger 64 cast integrally with thebracket 60. The hanger overlies the contact drum, and it issubstantially centrally located with respect to a pair of anking hangermembers 65 that are also cast integrally with the bracket 60 and serveto support pinch rolls 66, one at the feed side of the contact drum andthe other at the delivery side of the Contact drum.

A trunnion on each end of each pinch roll is journalled in a bearing 67which is Welded to the bottom of a screw 68. The screws 68 pass looselyupwardly through suitable holes in the hangers 65, to have nuts 69threaded on their upper ends. Springs 70 encircling the screws 68 andconfined between the hangers and the bearings 67 to serve yieldinglyresist upward motion of the pinch rolls as articles being sanded passthrough the sanding zone.

The upper or idler drum 19 is supported from the wall 12 for adjustmentbodily up and down, toward and from the contact drum, and for tiltingadjustment about a horizontal axis adjacent to the front face of thesupporting wall 12 and the inner end of the roll. The purpose of this isto enable the idler drum to be set to whatever position is necessary tokeep the endless abrasive belt 17 properly tensioned and running true onthe contact and idler drums.

The idler drum 19 is freely rotatably mounted on an idler shaft 72having its inner end fixed to the front face of a subsantially flatrectangular ange 73. The upper edge of the flange is centrally notchedto receive a supporting block 74, from which the tiange is hingedlysuspended by a transverse pivot pin 75. The ends of the pivot pinproject from the opposite side edges of the flange and are engaged inholes in the upper end portions of upright slide bars 76, between whichthe ange is received.

The slide bars 76 are confined between the opposite side edges of theange 73 and upright bars 77 which are xed on the supporting wall 12, andthey lie beneath outer bars 78 each of which is fixed to and overliesone of the fixed bars so as to overlap a portion of the slide bar 76thereunder laterally outwardly of the adjacent side edge of the flange73.

Hence, it will be apparent that the bars 76, 77, and 78 providecooperating stationary and movable guide means for the flange 73 and theidler shaft 72 carried thereby. The guide means, in turn, cooperate withthe front face of the supporting Wall 12 to provide spaced apart guidechannels that oppose and open toward one another, to slidably guide thebars 76 therein.

In this manner, the shaft flange is constrained to vertical motion alongthe front face of the supporting wall 12, without interfering withhinging motion of the ange relative to the guide channels, about theaxis of the hinge pin 75 so as to provide for whatever tiltingadjustment of the idler drum is necessary to make the abrasive belt 17run true on the idler and contact drums, The engagement of the shaftange 73 with the front face of the supporting wall 12, of course, limitsdownward tilting motion of the idler shaft on its hinge pin. l

Again in this case, it will be noted that the guide means comprising thebars 76, 77 and 78, is provided by inexpensive bar stock, as is truealso of the shaft flange 73 and the block 74 from which the idler drumis hingedly suspended.

Up and down adjusting movement of the idler drum is effected by turninga rotatable knob 80 in one direction or the other. The knob is seated onthe top of a lug 81 on the supporting wall 12, which lug projectsforwardly of the front face of the wall and has a vertical holetherethrough to loosely receive a screw 82. The upper end of the screwis secured to the knob, and the lower end of the screw is threaded intoa tapped hole in the block 74 opening to the top thereof. A thrustwasher 83 is preferably confined between the underside of the knob 80and the lug 81, since the weight of the idler drum and the tension onthe abrasive belt 17 can represent a substantially force pulling theknob 80 downwardly against the lug.

Tilting motion can be imparted to the idler shaft about the axis of thepivot pin 75 by turning the enlarged head 85 of an adjusting screw 86.The screw is threaded into the supporting wall 12 from its rear, and ithas its extremity arranged to bear centraly upon the back face of theidler shaft flange 73 at a point below the pivot pin 75.

Turning of the screw 86 in the direction to propel it forwardly willthus effect upward tilting of the outer end of the idler drum; whileturning of the screw in the opposite direction will effect lowering ofthe outer end of the idler drum.

Another feature of the invention is achieved by so determining the sizesand spacing of the drums around which the abrasive belt 17 is trainedwith respect to the sizes and spacing of the rolls around which the feedconveyor belt 14 is trained, that the two belts will have substantiallythe same length and width. Because of this, an abrasive belt such as isprovided as a replacement for the belt 17 can be trained around the feedconveyor rolls 20 and 21 as a substitute for the rubberized beltnormally -used for the feed conveyor. Hence, the conveyor belt 14 seenin IFIG. 1 can, if desired, be identical to the abrasive belt 17. Thiscan be highly advantageous when articles having certain peculiarcharacteristics are to be sanded.

From the foregoing description, together with the accompanying drawings,it will be readily apparent that this invention provides a belt sandingmachine in which substantial simplification of the mechanism has beenachieved without in any way sacrificing strength, or loss of accuracy inthe adjustment of its components or of the sanding operations of whichthe machine is capable.

We claim:

1. A belt type sanding machine of the type having an endless abrasivebelt trained over driving and idler drums that rotate on horizontal axesat different elevations, and means defining a horizontal bed over whicharticles can be advanced through a sanding zone beneath the bottom drumto be acted upon by the abrasive belt trained thereover, said machinebeing characterized by:

(A) a frame having an upright supporting wall from one face of which thedrums project axially;

(B) means supporting the bottom drum from said wall for rotation on afixed axis;

(C) a shaft rotatably carrying the idler drum;

(D) structure mounting the idler shaft on an upper portion of said wallfor bodily up and down motion relative to the bottom drum, and fortilting motion about a substantially horizontal axis crosswise of theidler shaft axis and close to said wall, said structure comprising (l) aflange secured to the end of the shaft adjacent to said face of thewall, said flange having opposite upright side edges,

(2) a block from which the vflanged end of the shaft is suspended, andto which the flange is pivotally connected to provide for said tiltingmotion of the shaft,

(3) supporting and actuating means connected to the block to mount thesame on said wall and to provide for up and down adjustment of the blockas well as retention thereof in anyV desired position of suchadjustment,

(4) cooperating stationary and movable guide means on said wall, themovable guide means being constrained to vertical motion on said wall,

(5) and means connecting said flange to the movable guide means so thatsaid up and down motion of the idler shaft is guided thereby;

(E) said flange and block having portions that are interleaved along theupper edge of the flange;

(F) a hinge pin pivotally connecting said interleaved portions of theflange and block to provide for said tilting motio-n of the shaft, saidhinge pin providing said means connecting the flange to the movableguide means;

(G) and said movable guide means comprising a pair of bars in lengthwisejuxtaposition to the opposite side edges of the flange, and havingportions into which the opposite ends of the hinge pin extend.

2. A belt type sanding machine having an endless abrasive belt trainedover driving and idler drums which rotate on horizontal axes atdifferent elevations, and a horizontal bed over which articles can beadvanced through a sanding zone beneath the bottom drum, said machinebeing characterized by:

(A) a frame having an upright supporting wall with a substantially flatfront face from which the drums project axially;

(B) means on said wall supporting the bottom drum for rotation on afixed axis;

(C) and means including a shaft to support the idler drum from said wallfor bodily up and down motion relative to the bottom drum, and furthercomprising (l) a flange on the inner end of the shaft having oppositeside edge portions,

(2) a pivot pin on which the flange is mounted for tilting motion abouta horizontal axis with the shaft axis spaced below the pin and with theopposite end portions of the pin projecting from said opposite side edgeportions of the flange,

(3) a pair of vertically disposed slide bars located in juxtaposition tosaid opposite side edge portions of the flange, and into which theopposite end portions of the pivot pin extend to connect the flangetherewith,

(4) and guide means on said wall which define vertical guide channelsfor said bars and which cooperate with said face of the supporting walland with said opposite side edge portions of the flange to confine thebars in the channels and to thereby constrain the idler drum to up anddown motion without interfering with tilt- 60 ing motion thereof aboutthe pin axis;

(D) and manually adjustable means carried by the supporting wall andconnected with said pin for holding the idler drum in differentpositions of vertical adjustment.

3. A belt type sanding machine which is characterized by:

'(A) a frame;

(B) means on the frame defining a rigid elongated bed having ahorizontal top over which articles can be advanced through a sandingzone from one end of the bed to the other;

(C) driving and driven drums carried by the frame for rotation onhorizontal axes at different elevations above the bed, with one of saiddr-ums at a 8 location adjacent to the top of the bed and in saidReferences Cited sanding zone; (D) two identical endless abrasive belts,one of which UNITED STATES PATENTS is trained about said drums;2,581,270 1/ 1952 McVey 51-140UX (E) and conveyor means on the bedoperable to c011- 5 3,504,458 4/ 1970 Rutt 51-135 duct articles throughthe sanding zone, comprising 2,791,070 5/1957 Schaller 51--138 rollmeans rotatable on axes substantially parallel t0 2,724,934 11 /1955Urquhart 51--135 those of the drums and having the second one of saidbelts trained thereabout, said roll means being HAROLD D. WHITEHEAD,yPrimary Examiner disposed close to the ends of the bed top and to 10constrain one stretch of the second belt to travel U.S. Cl. X.R.

along the topl of the bed Where it can. receive and 51-138, 140

carry articles to be sanded through the sanding zone during operation ofthe conveyor means.

